1. Field of Art
This invention relates to the improvement of an agricultural ground-working cultivator. More specifically it relates to an improvement of the center frame of a cultivator and support for a pair of opposing wings on the said cultivator.
2. Description of Prior Art
The need to till and cultivate soil for the planting of crops has been accomplished since the earliest days of civilization. More recently, tillage devices have increased in complexity and size, depending on the type of crops, quantity and soil being tilled. There has also been an increased emphasis on conserving natural resources resulting in these concerns being integrated in modem tillage systems. These concerns have resulted in larger and more complex tillage systems that assist in achieving these goals. A larger tillage system allows a single operator to perform tillage operations on a greater area. More sophisticated tillage systems further allow for the accomplishment of low till and no till farming techniques. Low till and no till farming encourages tilling, planting and fertilizing in a single pass of the tillage device or cultivator through the field. By only disturbing the soil a single time, there is less soil compaction, less moisture loss, less pesticides and herbicides needed and less fertilizer required. However, these larger and more complex tillage systems create complexities that were previously unknown in the art.
Previously, an agricultural tractor could pull a relatively small tillage device or cultivator. As the tillage device or cultivator moved over hills and similar undulations in the terrain all the ground-working implements maintained contact with the soil. The width of the tillage device was sufficiently small such that it generally did not have problems maintaining ground contact. However, as the tillage devices were increased in width, so as to be able to till a greater area in a single pass, the undulations in the ground resulted in the ground-working tools failing to always contact the earth. Also, to transport the tillage device or cultivator for the farming operations it was also necessary for the device to be capable of being collapsed to a width sufficient to be moved. To accomplish these goals, a center section with a set of pivotable wings was designed. The wings could pivot horizontally relative to the center section allowing the tillage device to accommodate some undulations in the ground. The wings could also be folded into the center section allowing for easy transport before and after farming operations. Eventually, an outer set of wings was added increasing the width of the tillage device. FIG. 1 illustrates the general configuration of a tillage device or cultivator. Specifically, there is a center section directly behind the tractor. There is a set of inner wings and outer wings respectively surrounding the center section. Some cultivators are folded into the transport position along an axis along the direction of travel; other cultivators are folded along a diagonal axis. In prior art cultivators, the wings can rotate on an axis in the direction of travel, the wings generally cannot rotate, flex or bend on an axis perpendicular to travel. Finally, the additional inner wings and outer wings create large additional draft forces on the frame of the cultivator. (Draft forces are the forces created when the ground-working tool is pulled through the soil.) These are complex problems to overcome, especially when considering the need for the tillage device to be a collapsed from its field operation mode to the compact transportation mode.
Consequently, the need exists for a linkage, which allows for the inner wings to move perpendicular relative to the center section of a tillage device. Also the need exists for a draft cable which helps distribute the draft load generated by the outer wings.